The present invention pertains to paperboard containers having reinforced corners, and in particular, to locking mechanism used in the paperboard container blanks to help maintain an erected container form.
It is well known to form paperboard containers that use extra wall layers to increase wall thickness at the corners of the container to improve stacking strength. Such containers are typically used with products that are unusually heavy, e.g., frozen meat, paper files, books, canned goods, etc.
One examples of such a container is shown in U.S. Pat. No. 5,000,377 to the present inventor. This prior container uses doubled-over reinforcing panel sub-assemblies at its interior corners and glue flaps about its exterior upper surface. This container is typically formed by machine. However, this can be a problem for small business that cannot afford the huge investment required to install tray formers and case sealers. To date, small manufacturers have had to settle for much more expensive and less efficient box styles than their large competitors. These expensive and less efficient box styles include xe2x80x9cswing underxe2x80x9d styles, double wall RSC""s (regular slotted containers), and various combinations of hand-erected trays and HSC""s (half slotted containers), all of which require much more board for a given endurance level.
Thus, a need exists for an efficient and less expensive container that may be used with these heavier products and that include superior locking mechanisms. The preferred container should be capable of relatively easy formation from paperboard blanks without the use of machinery or tooling. The present invention is directed to fulfilling these needs and others as described below.
In accordance with the teaching of the present invention, an efficient and easily hand-formed container is provided from a one-piece paperboard blank. The invention includes various inventive features which may be used singularly or in combination.
In one embodiment, the features are combined and the container includes a bottom panel, first and second opposed side walls, and first and second opposed end walls. A top lid panel connects to the first side wall and a bottom lid panel connects to the second side wall. A locking tab is formed in the first side wall and includes a thumb notch located within the tab. The top lid panel includes a pair of cover latches located on the outer corners thereof. A bottom lid panel connects to the second side wall and includes a pair of alignment tabs located on the outer corners thereof.
Each end wall includes a hand hole lock, a lock slot, and a recess located along an end wall exterior edge. The lock slot is located between the recess and the hand hole lock. Each end wall further includes first and second reinforcing panel sub-assemblies, each having an inner panel, a middle panel, and an outer panel. Each inner panel includes a pair of recesses with an intermediate tab located along an inner panel exterior edge. Each middle panel includes a locking slot near a middle panel exterior edge. The outer panel of the first sub-assembly includes a recess along an outer panel exterior edge and a hand hole.
As assembled, the locking tabs are disposed within the lock slots with the intermediate tab of the inner panel at least partially inserted into the locking tab thumb notch. The cover latches are inserted into the locking slots of the end walls. The alignment tabs are positioned in the aligned recesses of the outer panel and the end wall.